


The Safe Word is "Duffle Bag"

by equilateral_asshat



Category: Gravity Falls
Genre: Archived From My Tumblr, F/M, Honorable Mention: Wendy Corduroy taking Dip's virginity, pinecest - Freeform, pinescest - Freeform
Language: English
Status: Completed
Published: 2018-12-15
Updated: 2018-12-15
Packaged: 2019-09-18 11:42:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 964
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16994343
Author URL: https://archiveofourown.org/users/equilateral_asshat/pseuds/equilateral_asshat





	The Safe Word is "Duffle Bag"

“C’mon, Dipper! Quit stalling, it’s not like neither of us haven’t done this before!”

Dipper chewed on his lower lip; Mabel was right, of course. They had both long ago given up their respective virginities. Not to each other, however; Mabel did the do with her high school boyfriend, after their senior prom. The two had thought they were going to stick together throughout college and the like, but when they got accepted to different universities, they had decided distance would be too stressful and split.

Dipper, however, hadn’t spent his V Card until they had a going-away party at the Mystery Shack, the last summer they had spent in Gravity Falls after they graduated high school. Both of them had gotten into the same school, and decided to revisit their old summer stomping grounds before they had to trudge through college. Towards the end of the party, Wendy had pulled Dipper aside to give him a “special gift” she insisted he would never forget. And, she had been right, losing his virginity to his long-standing, childhood love/crush had been a wild night that he’d never forget. Especially if the pictures she had told him to snap with his phone were any indicator.

“I know, Mabes, and I dunno why I’m being so difficult about it now,” he admitted. Their relationship was one of those weird, forbidden things you just didn’t do; yet a few months ago they had both confessed long standing, once buried feelings for one another. And now, twins were more-than-twins. Currently, they were more-than-twins-poised-and-ready, to finally launch into the next part of their relationship, the _physical_ side of it. Dipper had been anticipating this moment for a week now, and was excited!

So why, he mentally begged himself, was it so hard to make that last move that made the difference between grinding and intercourse?! What roadblock was there?

“Are you afraid it won’t be good?”

“What?! No, Mabel! I love you, and anything I do with you will be amazing!” he said, rolling off to the side to sit up and groan into his open palms.

“Are you afraid you’ll hurt me?” she pried, and he sighed with a small shrug.

“I dunno, maybe a little? Which is weird, because I’m pretty sure you’re tougher than me, so I should be more afraid for my own safety.” His sister laughed and playfully socked him on the elbow. He grunted, a hand lifting to rub at the spot there. “Ow! Heh, see?”

“Pfff, c’mon, bro-bro, you won’t hurt me. We’ve both had our share of horizontal-mambo’s with other folks, we know what we’re doin’!” she reassured, beaming a smile his way.

“Yeah, yeah I guess you’re right…” he relented, before playfully tackling her back onto the bed and nipping at her collarbone. She squealed, playfully wiggling under him.

“EEK! Haha, see, there ya go,” she murmured, shifting to plant a smooch on his forehead. “Now gimme the full constellation!”

“The… wha…?”

“Gimme the _Big Dipper_.”

“Oh god, I should withhold sex from you just for calling it that!” he laughed.

“Stop yammering and start frickle-fracking, dang it! Just close your eyes and pretend that I’m Wendy!”

One quick thrust, and suddenly Mabel’s voice was gone. Her head rolled back as her back arched, a gasp weaseling its way out of her throat. She had not expected such a powerful, hearty thrust from her brother. He was always so gentle, so delicate with her. This was a surprise, although not an unpleasant one.

“Ho-holy frig, Dip! I di-” she started, but another heavy slap of thigh-to-thigh forced her voice into an afterthought yet again. Before she could even manage to get another syllable out, he flipped her over, grabbed her by both wrists and used the leverage to tug himself against her again, and again.

As her vision swam with stars and her mind was reduced to static, she managed to wonder just what she had awakened in her brother.

=========

“S-sorry, Mabel, I shouldn’t have taken you quite so literally,” Dipper said, handing her a bag of ice, wrapped in a hand towel. She gingerly placed the bundle between her thighs and squeezed, wincing at first, then letting out a gentle hum of relief.

“You’re fine, Dip-dop. I didn’t realize telling you to act like I was Wendy would trigger something like that in ya, is all.” She adjusted the bag a tiny bit, groaning as she did. “Or that you even had that in you, what the hey-hey?”

“Well, uh, you know how Wendy was my first, right?” he said, rubbing the back of his neck. She nodded. “Well, when I was acting all shy and nervous and junk with it being my first time, and worried that I’d, uh… ‘go off’ too soon, she told me not to worry, give it my all. After I got off the first time, she told me that there wasn’t anything I could do to break her, to really ‘let her have it’, so I did and she went wild for it. It always kinda stuck with me, so when I thought about it…”

Mabel just nodded, smiling weakly. “Okay, yeah, I gotcha. Telling you to act like I was Wendy was a bad idea since I didn’t know how it went down with you. Oof…”

“I’m sorry our first time together was bad, sis. I-” Dipper began, but she pressed a fingertip to his lips.

“Nuh uh, don’t you dare apologize for that.” He quirked a brow at her. “Bro, that was _amazing,_ ” she admitted, falling backwards with a heaving breath. He sprawled out on his side next to her, gently twirling some of her hair around his finger.

“Next time, though,” she huffed out, “we gotta choose a safe word.”


End file.
